The present invention relates to a torque signalling wrench, and, more particularly, to a simplified structure for such a wrench enabling low cost production of the wrench including cost of manufacturing parts and assembly.
Torque limiting wrenches are known. The known wrenches have a wrench shank structure associated with a handle for the wrench and a torque responsive unit comprising a swivel type connection is also associated with the handle and provides for relative movement between elements of the torque responsive unit for limiting the torque applied by the wrench. In the known wrenches, the torque responsive unit is a unit which is fabricated separately and incorporated into the handle for the wrench. These units complicate the manufacture of torque wrenches because of the nature of the parts and the assembly operations required, thereby, increasing the cost of such wrenches.
It is an object of the present invention to provide a torque wrench which signals when the applied torque exceeds an adjustable threshold and in which requires a minimum of simple parts which are such that prefabricated torque responsive units are not necessary, the fabrication the parts only requiring simple machine or forming operation with the assembly of the torque signalling wrench being a simple assembly operation and the design enabling standard production wrench heads with handle shanks to be utilized.